This invention relates generally to a towing apparatus and, more particularly, to a towbar apparatus which may be quickly and easily operated by one person for towing aircraft when not using engine power.
Towbars and aircraft tugs are needed to move aircraft in and out of maintenance and storage hangars when the aircraft is not operating under engine power. These towing apparatus are especially necessary in the case of moving helicopters. Towing aircraft is especially challenging at small airports where the pilot may have to manipulate the towing apparatus by himself.
Various devices have been proposed in the art for towing aircraft. Although assumably effective for their intended purposes, the existing devices do not enable a user to adjust both laterally and vertically the aircraft wheel assembly gripping mechanism by himself while maintaining his position adjacent the hitch assembly.
Therefore, it is desirable to have an aircraft towbar apparatus which may be coupled both to a towing vehicle and to an aircraft wheel assembly without a single operator having to walk between the tow vehicle and aircraft. Further, it is desirable to have an aircraft towbar apparatus having aircraft wheel assembly grippers that may be adjusted vertically and laterally by a user from a single position adjacent the towbar hitch assembly.
An aircraft towbar according to the present invention includes first and second tubular members having respective proximal and distal ends relative to an operator""s position during use. A hitch assembly is releasably coupled to respective proximal ends, the hitch assembly having overlapping plates that are pivotal relative to one another and formed for releasable attachment to a towing vehicle. An inwardly protruding gripping member is releasably coupled to each distal end of first and second tubular members for gripping an aircraft wheel assembly when properly positioned thereabout. A wheel assembly having a pair of wheels connected with an axle is rotatably coupled to the tubular members at a position spaced from the distal ends thereof. Therefore, the wheel assembly serves as a fulcrum for operation of the tubular members as levers. In other words, a downward movement of the proximal ends causes an upward movement of the distal ends, and vice versa.
The towbar apparatus further includes a scissor jack extending between the first and second tubular members for selectively varying the lateral spacing between the tubular members. The jack is slightly spaced apart from the distal ends such that the distal ends are increasingly spaced apart when the scissor jack is expanded while the proximal ends remain coupled together by the hitch assembly. The scissor jack includes scissor arm mechanisms that open or close upon rotation of a threaded rod. An elongate handle bar is coupled at one end to the threaded rod and extends to an opposed end supported above the hitch assembly with a bracket. A crank handle is fixedly attached to the elongate handle bar over the hitch assembly. Therefore, a user may open or close the scissor jack so as to adjust the lateral space between the gripping members by rotating the crank handle without having to move away from a hitch assembly position. The apparatus further includes a support handle at the distal end to enable the user to vertically adjust the position of the gripping members. Accordingly, a single user may easily manipulate, both vertically and laterally, the position of the gripping members whereby to couple one end of the towbar apparatus to an aircraft wheel assembly while maintaining a single position whereby to also couple another end of the apparatus to a towing vehicle.
Therefore, a general object of this invention is to provide a towbar apparatus for towing aircraft with a towing vehicle.
Another object of this invention is to provide a towbar apparatus, as aforesaid, which may be coupled to an aircraft wheel assembly and to a towing vehicle from a single user position.
Still another object of this invention is to provide a towbar apparatus, as aforesaid, having aircraft wheel assembly gripping members that may be positioned vertically and laterally about an aircraft wheel assembly from a single user position.
Yet another object of this invention is to provide a towbar apparatus, as aforesaid, in which the lateral space between a pair of tubular members may be varied by rotating an elongate crank handle.
A further object of this invention is to provide a towbar apparatus, as aforesaid, in which a hitch assembly includes pivotal plates which accommodate the varying of lateral space between distal ends of the tubular members.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.